Shell crimper



L. A. PACE SHELL CRIMPER A ril 11, 1967 Filed June 22, 1965 INVENTOR. ZELA/VD A. PACE A TTORA/EKS United States Patent 3,313,203 SHELL CRIMPER Leland A. Pace, 545 S. Los Robles, Pasadena, Calif. 91106 Filed June 22, 1965, Ser. No. 465,850 10 Claims. (Cl. 86-41) This invention relates to a crimper for closing the open ends of shotgun shells, as required for loading and reloading the same.

Devices for fluting the open ends of shotgun shells are known and regularly used in loading and reloading the shells. Such devices customarily include a tube which is shoved over the open end of the shell, with blades on the inside of the tube to deflect the wall of the shell toward its central axis. Then a tamper is lowered to crush the fluted cell to a closed condition. Such a technique, while it is the best presently known, has many drawbacks. One is the rough treatment which it gives to the paper of which the shell is made, and another is the irregularity of result.

It is an object of this invention to provide a crimper for closing shotgun shells which crimper closes the shell in a smooth operation that produces a uniform product from shell to shell, even on worn shells.

A crimper according to this invention includes a body which has a cavity with a central axis and an open end to receive the open end of the shell. 7

Within the cavity and defining the shape thereof are certain surfaces. One of said surfaces is a peripheral bounding surface that is so disposed and arranged as at least partially to engage the shell and hold it in coaxial alignment with the axis of the cavity. A plurality of divider edges adjacent to the boundary wall extend radially toward the central axis. There is a deflector surface between each pair of divider edges, which latter surfaces extend toward the central axis from the boundary wall. Each deflector surface forms, adjacent to its intersection with the boundary wall, a fragment of a surface of revolution that is generated around the central axis, whose generator bends toward the normal to the axis as it extends toward the central axis. A plurality of inverter surfaces extends from and interconnects said divider edges and deflector surfaces, there being oneof said inverter surfaces on each side of each of said divider edges. The inverter surfaces extend laterally away from said divider edges as they extend axially away from the open end, each pair forming a dihedral angle with the respective divider edge as the dihedral edge.

According to a preferred but optional feature of the invention, the generator of the deflector surface bends through the normal and extends to form an obtuse angle with the central axis, facing the open end.

The above and other features of this invention will be fully understood from the following detailed description and the accompanying drawings, in which:

FIG. 1 is an end view of one embodiment of the invention;

FIG. 2 is a cross-section taken at line 2-2 of FIG. 1;

FIG. 3 is an' end view of another embodiment of the invention;

FIG. 4 is a cross-section taken at line 44 of FIG. 3;

FIGS. 5 and 6 are end and side views, respectively, of the end of a shotgun shell'closed by the devices of FIGS. 1 and 3; and

FIGS. 7 and 8 are cross-sections taken at lines 7-7 and 88, respectively, of FIG. 5.

The presently preferred embodiment of the invention is shown in FIG. 1. This device is intended to be pressed against the open end of a shotgun shell for the purpose of closing it. In use it is usually attached to a leveractuated linkage so as to be reciprocably moved, thus to exert a compressive force on the open end of the shotgun shell. Because such reciprocating mechanisms are widely known, none is shown here. The crimper 10 in cludes a body 11 having a cavity 12 with an open end 13. The cavity has a central axis 14. A threaded hole 15 is provided for threaded attachment to the device which will move the crimped axially.

The open end of the crimper has a bell mouth 16 intended to guide the shotgun shell into the cavity so that its central axis coincides with the axis of the cavity. The cavity is partially defined by a peripheral boundary surface 17 which is preferably cylindrical as shown and about the same diameter as the outer diameter of the shotgun shell. This peripheral boundary surface will hold the shell in the aforesaid alignment.

Axially farther away from the open end of the cavity there are disposed surfaces for the purpose of turning in the open end of the shell, which shell end is initially a circularly cylindrical tube, to achieve the configuration shown in FIGS. 5-8. As can best be seen from these figures the initially open end 20 of a shotgun shell 21 is intended to be crimped over by forming a plurality of folds 22 and transition surfaces 23. There is a small central opening 24 left in the shotgun shell which is smaller than that shown in FIG. 5 but this is closed by materials contained within the shotgun shell as is well known in the art. As can best be seen from FIGS. 7 and 8 the shell is crimped so that the fold line 25 extends down and inside the shell, and the transition surfaces form the upper end.

In the prior art devices, attempts have been made to flute the side portions which are turned in in this invention, and then compresssive forces have been exerted on the end to crush the material in the center. In contrast, this device guides the material of the shell so as to follow smoothly developed fold lines and transition surfaces, and thereby moves in straightforward flow, without crushing, to form a smooth well formed, uniform, crimped end. This objective is achieved by providing a plurality of divider edges 30. In this embodiment six divider edges are provided, because six-part division appears to be optimum for shotgun shells of all types and sizes. It will be recognized that more or fewer of the divider edges and the accompanying surfaces may be provided. Preferably the divider edges are somewhat sharp although they may be slightly beveled if desired. Their purpose is to engage the end of the shotgun shell at precisely evenly spaced apart points, thereby evenly to divide up the wall and end areas of the shell.

In the embodiment of FIG. 1, the divider edges extend from the boundary surface inward toward the central axis where they intersect. The divider edges lie substantially normal to the central axis and form a non-obtuse angle therewith. In FIG. 2 it will be noted that these edges extend slightly away from the open end as they extend toward the central axis. However, this angle when it exists will ordinarily be on the order of only a few degrees.

Between each pair of divider edges there is disposed a deflector surface 35. All of the deflector surfaces are congruent. They are formed by a generator 36 which can be seen in FIG. 2. Adjacent to the peripheral wall, this generator lies at an acute angle to the central axis and then bends through a point 37 where a tangent thereto lies normal to the axis and then extends to a position where it lies obtuse thereto, all of these angles being considered with reference to the open end.

At each side of each divider edge there is a pair of inverter surfaces 40, 41. These inverter surfaces form a dihedral angle which faces away from the open end to form a non-planar structure. Each divider edge forms the dihedral angle for a respective pair of inverter surfaces, thereby to form the dihedral angle. In the embodiment of FIG. 1, the inverter surfaces themselves are concave toward the open end of the cavity, the dihedral angles being convex in the same sense. These inverter surfaces are not precisely planar, nor are the dihedral angles sharp linear edges, but the effect is that of a dihedral structure. Near the respective dehedral edge the inverter edges form a nominal angle of about 1525 facing away from the open end. The peripheral boundary surfaces 17 and the inverter surfaces generally define fold regions 42. There are as many of these fold regions as there are divider edges.

Another embodiment of the invention is shown in FIG. 3 which comprises a crimper 50 having a body 51 with a cavity 52 that has an open end 53. The cavity has a central axis 54. There is a threaded hole 55 for mounting the device to auxiliary equipment.

This device includes a bell mouth 56 and there is located axially farther into the cavity a peripheral, preferably circularly cylindrical, boundary surface 57 as in the device of FIG. 1.

This embodiment includes a plurality of divider edges 60 which extend axially deeper into the cavity as they extend toward the central axis preferably at an angle of between about 20. They are rather straight, and do not reach the central axis. Instead, there is a central region 61 lying inside a plurality of substantially conical deflector surfaces 63. Central region 61 is substantially conical, and which extends radially outward to meet the deflector surfaces at lines 64. In this embodiment as in that of FIG. 3, the surfaces of revolution (region 61 and surfaces 63) are fragments rendered discontinuous by divider edges and inverter surfaces. These deflector surfaces are fragments of surfaces of revolution formed by a generator 65 (FIG. 4) which generator is substantially straight (although it may be slightly curved in a concave manner) and extends from point 66 to line 64. Adjacent to the peripheral wall, the generator forms an acute angle with the central axis, the angle opening toward the open end of the cavity. It bends at line 64, where a small radius may be formed, at which a tangent to the generator is norm-a1 to the axis, and then is straight through region 61, forming an obtuse angle with the central axis.

Inverter surfaces 70, 71 are formed in pairs on opposite sides of the divider edges. These inverter surfaces may be planar as shown, or may be somewhat concave. They form a dihedral angle on the order of about There is formed between the inverter surfaces and the peripheral wall a plurality of fold regions 72.

The operation of the device should be evident from the foregoing. The crimper is forced against the open end of the shotgun shell which at the beginning is circularly cylindrical. It is centered by the peripheral wall and its end first encounters the divider edges which neatly and accurately divide it up into six regions. Then as the shotgun shell and the crimper are forced against each other, the regions between the divider edge strike the deflector surfaces and are by them deflected inwardly toward the central axis, those portions of the shell which contact the divider edges being directed at least initially inwardly.

By reference to FIG. 1 it will be seen that there is a continual flow of material down the deflector surface where, as it approaches the central axis, it encounters the inverter surfaces and this, combined with the accurately determined mold point which determination was made by the divider edges, will cause a fold such as fold 22 to be formed and to progress inwardly into the shell itself. When the shell and the crimper have been forced far enough together, a crimped structure results which has the appearance of FIGS. 5 and 6 which is a smoothly formed substantially fiat device which may further be tamped if desired. The folds are evenly spaced apart, and there is no sharp point of creasing or discontinuity in the shell structure.

The device of FIG. 3 functions in substantially the same manner. However, instead of compressing the material between the two inverter surfaces at a region close to the central axis, the deflector surface between points 66 and line 64 causes a fold and departure of direction to be made toward the axis. Then the shell material strikes region 61 (which forms a continuation of the deflector surfaces and guides the material toward its folded-in condition). In either event the folded end of the shell results as shown in FIGS. S8.

There is thereby provided in a simple structure a unitary device for closing and crimping shut the end of the shotgun shell which guides the material of the shell in a smooth transitional motion, avoiding sharp discontinuities and folds which would be destructive of the material.

This invention is not to be limited by the embodiments shown in the drawings and described in the description which are given by way of examples and not of limitation but only in accordance with the scope of the appended claims.

I claim:

1. A crimper for closing the open end of a shotgun shell, comprising a body having a cavity with a central axis, and an open end to receive the open end of the shell, there being within the cavity and defining the shape thereof the following surfaces: a peripheral bounding surface so disposed and arranged as at least partially to engage the shell and hold it in coaxial alignment with the axis of the cavity; a plurality of divider edges adjacent to the boundary wall and extending radially toward the central axis; a deflector surface between each pair of divider edges, extending toward the central axis from the boundary wall, each said deflector surface forming adjacent to its intersection with the boundary wall, a fragment of a surface of revolution generated around the central axis whose generator is inclined relative to the central axis; and a plurality of inverter surfaces which extend from and interconnect said divider edges in pairs and deflector surfaces, there being one of said inverter surfaces on each side of each of said divider edges, said inverter surfaces extending laterally away from said divider edges as they extend axially away from the open end, each pair forming a dihedral angle with a respective divider edge functioning as the dihedral edge.

2. A crimper according to claim 1 in which the divider edges form a non-obtuse angle with the central axis facing the open end.

3. A crimper according to claim 2 in which the said non-obtuse angle is substantially 4. A crimper according to claim 1 in which the divider edges intersect on the central axis.

5. A crimper according to claim 5 in which the inverter surfaces extend from the peripheral walls to the intersection of the divider edges.

6. A crimper according to claim 1 in which the ends of the divider edges closest to the central axis are spaced apart from one another.

7. A crimper according to claim 1 in which the generator of the deflector surface bends through the normal and extends to form an obtuse angle with the central axis, facing the open end.

8. A crimper according to claim 7 in which the ends of the divider edges closest to the central axis are spaced apart from one another, and in which the region inside the termination point of the generator is substantially conical.

9. A crimper according to claim 1 in which the inverter surfaces are concave.

10. A crimper according to claim 1 in which the inverter surfaces are substantially planar.

No references cited.

BENJAMIN A. BORCHELT, Primary Examiner.

P. A. SHANLEY, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,313,203 April 11, 1967 Leland A. Pace It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 66 Signed and sealed this 14th day of November 1967.

for "mold" read fold (SEAL) Attest:

EDWARD J. BRENNER Edward M. Fletcher, Jr. Attesting Officer Commissioner of Patents 

1. A CRIMPER FOR CLOSING THE OPEN END OF A SHOTGUN SHELL, COMPRISING A BODY HAVING A CAVITY WITH A CENTRAL AXIS, AND AN OPEN END TO RECEIVE THE OPEN END OF THE SHELL, THERE BEING WITHIN THE CAVITY AND DEFINING THE SHAPE THEREOF THE FOLLOWING SURFACES; A PERIPHERAL BOUNDING SURFACE SO DISPOSED AND ARRANGED AS AT LEAST PARTIALLY TO ENGAGE THE SHELL AND HOLD IT IN COAXIAL ALIGNMENT WITH THE AXIS OF THE CAVITY; A PLURALITY OF DIVIDER EDGES ADJACENT TO THE BOUNDARY WALL AND EXTENDING RADIALLY TOWARD THE CENTRAL AXIS; A DEFLECTOR SURFACE BETWEEN EACH PAIR OF DIVIDER EDGES, EXTENDIGN TOWARD THE CENTRAL AXIS FROM THE BOUNDARY WALL, EACH SAID DEFLECTOR SURFACE FORMING ADJACENT TO ITS INTERSECTION WITH THE BOUNDARY WALL, A FRAGMENT OF A SURFACE OF REVOLUTION GENERATED AROUND THE CENTRAL AXIS WHOSE GENERATOR IS INCLINED RELATIVE TO THE CENTRAL AXIS; AND A PLURALITY OF INVERTER SURFACES WHICH EXTEND FROM AND INTERCONNECT SAID DIVIDER EDGES IN PAIRS AND DEFLECTOR SURFACES, THERE BEING ONE OF SAID INVERTER SURFACES ON EACH SIDE OF EACH OF SAID DIVIDER EDGES, SAID INVERTER SURFACES EXTENDING LATERALLY AWAY FROM SAID DIVIDER EDGES AS THEY EXTEND AXIALLY AWAY FROM THE OPEN END, SAID PAIR FORMING A DIHEDRAL ANGLE WITH A RESPECTIVE DIVIDER EDGE FUNCTIONING AS THE DIHEDRAL EDGE. 